It is important to define the tax rate for every product. The tax rate can be set while adding an event,

This can be done as: Events -> Add new



On this page, the price along with the tax rate has to be defined for the event.



Alternately, the tax rate can also be defined/edited once the event has been added. This can be done as: Events -> Manage events



On this page, the price along with the tax rate can be edited for the event.